The objective of this proposal is to characterize the biologic and physiochemical properties of a growth factor which has been found in prostatic tissue from patients with benign prostatic hyperplasia. The biologic activity of prostatic growth factor (PrGF) will be characterized by determining the spectrum of response of a number of rat and human tissues and cells. Detailed information will be sought regarding the response of both epithelial and fibrostromal elements of nomal prostate and BPH to this growth factor. The molecular weight and other physiochemical properties of PrGF will be determined using standard techniques in order to compare PrGF with the properties of other known growth factor.